Furnace for pulverous fuel



msmw

K. H. V. VON PORAT FURNACE FOR PULVEROUS FUEL Patented .luly 17, 1923.

KARL HJALMAR VILHELM VON PORAT, OF STOCKI'IOLM, SWEDEN, ASSIGNOR TO MO- TALA. VERKSTADS NYA AKTIEBOLAG,

IPOBATION.

OF MOTALA VERKSTAD, SWEDEN, A COR- FUBNACE FOR PULVEROUS FUEL.

Application filedNovember 4", 1919. Serial No. 335,629.

To all whom it may concern: p

Be it known that I, KARL HJALMAR VIL- HELM VON PORAT, engineer, subject of the King of Sweden, residing at Vastra Tradgardsgatan 4, Stockholm, Sweden, have in-' vented certain new and useful Improvements in Furnaces for Pulverous Fuel, of

e which the following is a specification.

The present invention relates to boiler furnaces burning pulverulent fuel, particularly for locomotives, in which the fuel together with a gaseous medium, such as air, is forced below an arch of refractory material so'that the mixture of air and fuel is caused to pass along the under side of the arch and then along the upper side thereof, before it escapes through the fire tubes 1n the boiler.

The invention has for its purpose to provide a simple and strong construction, which is adapted to burn all the different kinds of 'pulverulent fuels;'both the easily ignited kinds, such as fat pit coals rich in gases, as well as those not readily ignited, such as poor pit coals or coarse grained peat powder.

A practical embodiment of the invention is shownin the accompanying drawings in which:

Fig. 1 shows the furnace in vertical section. Fig. 2 is a section on the lines GrH and I-K of Fig. l. The left half of Fig. 3 is a section on the line A--B andthe right half is a section on the line CD of Fig. 1. Fig. 4 is a section on the line E-F of Fig.

1, and Fig. 5 shows a detail on a larger scale.

1 indicates a plate mantle and consists of a crown sheet, side sheets and a flue. sheet, which form the top and side walls of the fire box or furnace and the rear end of a boiler 2. From the flue sheet, to which the rear ends of the fire tubes, passing through the water in the boiler, are attached in usual way, there projects upwardly in an inclined position an arch 3 of refractory material. In Figs. 3, 4 and 5 the means for supporting the arch is shown in detail. This means consists of screw bolts which are screwed into the side sheets at opposite sides, and iron beams 16, resting on these screw bolts. The edges of the arch 3 are formed of book shaped bricks which engage the beams 16 and bolts 15 in order to support the arch.

The spaces between these bricks and the with a wall of refractory material 12. Y

The bottom of the furnace chamber as well as the lower part of its side walls also consists of refractory material, except that part of the bottom which is formed by the grate 6, which is arranged in the front part of the furnace below the arch. The bottom part of refractory material behind the grate is indicated by 4, and the lateral walls confining the lower part of the furnace chamber 'are indicated by 28. A tube 5 for supplying the pulverulent fuel opens into a channel 18 in the bottom part 4. The fuel is impelled through and from the tube 5 in the combustion chamber by the draught in the furnace, or it may be blown into the chamberwith a gaseous mediumsuch as air. The arrangement is such that at least the inner part of the channel 18 is located below the arch 8. Although the bottom part 4 is inclined, it has a relatively great extension horizontally'at that point where the channel 18 is located, so that this latter may be rela tively long. This channel forms a primary mixing and heating channel for the fuel.

As will'be clearly seen from Fig. 3, the brick-work walls 28 which constitute the sides of the lower part of the combustion chamber, do not extend to the arch 3, but the upper part of the chamber between the arch and the grate is bounded laterally by the side and crown sheets 1, which is in contact with water andthus cooled. The channel 18, in which the tube 5 projects, opens into the said lower part of the combustion chamber that is between the brick-work walls 28. It should be noted that the arrangement is such that the space between the brick-work walls 28 is much narrower than the upper part of the chamber below the arch 3, and between the side sheets. Preferably, the said lower part should be only about'o'nehalf as wide as said upper part. As the channel 18 is horizontal, the mixture of air and fuel flows forwardly to the front part of the combustion chamber below thev arch and between the brick-work walls 28, and then rearwardly along the arch between the which canjfswing downwardly around the pivots*7 for emptying-the slag formed in the furnace. The free ends of the grate halves are held in their upper working-position, shown in the drawing,;by means of the devices which serve to swing the same;

. .Theispace below the grate is enclosed by a leasing 29. ggThi-s casingisrprovided with a damper or (1001134, which in turn'is preferably provided w'ith ,airinlet openings, contnollableYfrom the cabof the locomotive.

' In the'embodiment shown, the front grate.

half can be operated from the vcabofithe locomotive. Said grate, half ,is connected by means of a linlr30 with an arm- 31 on a shaft 32; which is mounted in the casing 29 and which isprovided outside of the casing I with an .arm 35, which, by means. of a suitable link and lever device is connected with a handle conveniently accessible from the cab ofthe locomotive. The rear gratehalf is held in its upperposition by a connection 35. ,Whic h. iS- wQessible from the underside the bottom of'the casing.

ofwth e casing and which, bymeans of a pin or the li,ke, is secured to a projection 36 on "In h rear, of the furn e p I ace below. the usual firing opening 23, there are air inlet channels l Oflwhich are ,enclosed by,brick-work and which are arranged in such a way that the air, flowing-into the same passes forwardly into the chamber below the arch 3. Theupper confining wall of said air channels is formed by a cross member 11. The air comes intothe channelslO through an inlet 8, which :is attached to the underside of the'furnace and which isv provided with a door or damper 17. This damper is preferably arranged so as to .be controlled by devices accessible from the cab of the locomotive] k v T When using easily ignitible fuel, all or the greater partof the combustion air is supplied through. the grate 6, but a part may enter through the inlet 8 and chan nels 10.

[When using fuel that is not readily ig-i' nited,f care should be taken not to supply-too xnuch'airflthroughi the grate 6, as too much air excessively reduces the temperature, so that the ignition and thecombustion will be lncompleteor fail. Therefore, the greatest v part of the combustion air, underthese circu'm'stance's', is

8IaI 1d10. 1

f furnace can be, fired up with wood and 100 1311 the usual manner and about as rapidlyl'lasis,usual, in furnaces fired with coal. when firing with pulverulent fuel it is not necessaryin most cases to have a admitted through the inlets passes through it without combustion, to

serve as combustion air for igniting the pulverulent fuel. v

The casing 29 below the grate, as well as the inlet 8 throughlwhich air is'supplied to the air channels 10, serves to. receivethe ashes. I l v I I The member v'11 above the air; channels 10 serves partly to prevent wood or. coal from falling down into the inlet 8 and forming a fire in this inlet, which fire would soon injure the inlet 8, and partly'to guidethe air from the channels 10: forwardly in a direction away fromthe flue sheetzl, so that the air will. not cool the flue-sheet but will enter the combustion ehanneland support combustion of the fuel therein. In order to obtain a better heat insulation for the lower part of the combustion chanr hen-which part is confined by the brickwork 28, the space 13 between the bricle. work 12 and 28, and the side sheets ,enolosing said brick-work, is filled up with ashes An annular opening is deft around the pipe 5, whereit enters the channel 1 8,s0 that a small amount of air may pass therethroughfrom the inlet 26, to holdthe fuel in suspense in. the channel 18 orto serve for the combustion of the fuelwhen onlyla very small quantity is used.

Itis thus to be observed that, according to the present invention, there are threedifferent air inlets arranged in a peculiar mannerso that means are provided whereby the air supplycan be controlled according to the quality of ,the fuel being used. Through two'of the air inlets, namely the; channels 18 and 10, the air flows forwardly into the combustion chamber below the 1 arch 3 while .the air flowing through the grate openings,

which form. the third air inlet, passes upwardly into the combustion.chamber. I

The channel 18 whichadmits both air and fuel, is located between the two other. air inlets both horizontally and vertically. The upper surfaceof1 the middle part of the furnace bottom, which surface'is located behind I the gratebut below the arch 3. is inclined soas to converge rearwardly with. the under surface of arch 8. Hence av viewofi' the whole grate 6 can be obtained through the firing opening23, and the grate may, also be cleaned by the use of astraight, tool.

lVhat claim is 1. In a furnace for different kinds offuel, the combination of a combustion chamber, a firing openingv inthe rear. end wallof; said chamber an arch dividing said chamber into an upper and a lower compartment communicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting rearwardly beyond the said grate, the rear part of the bottom of the chamber being composed of refractory material, and means for causing one kind of fuel to flow from the rear part of the chamber first forwardly to the front end of the lower compartment then rearwardly to the rear part of the upper compartment and then forwardly along the upper side of the arch before escaping from the chamber.

2. In a furnace for different kinds of fuel, the combination of a combustion chamber, a firing opening in the rear end wall of said chamber, an arch dividing said chamber into an upper and a lower compartment commit nicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting rearwardly beyond the said grate, the rear and lateral parts of the bottom of the chamber being composed of refractory material, and means for causing one kind of fuel to flow from the rear part of the chamber first forwardly to the front end of the lower compartment, then rearwardly'to the rear part of the upper compartment and then forwardly along the upper side of the arch before escaping from the chamber.

3. In a furnace for different kinds of fuel, the combination of a combustion chamber, a firing opening in the rear end wall of said chamber, an arch dividing said chamber into an upper and a lower compartment COIDHHL nicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting rearwardly beyond the said grate, the rear part of the bottom of the chamber being composed of refractory material, means for causing one kind of fuel to flow from the rear part of the chamber first forwardly to the front end of the lower compartment, then rearwardly to the rear part of' the upper compartment and then forwardly along the upper side of the arch before escaping from the chamber, and a horizontal channel forming an air inlet arranged in the rear part of the bottom of the chamber composed of refractory material, said channel being partially located below the said arch.

l. In a furnace for different kinds of fuel, the combination of a combustion chamber, a firing opening in the rear end wall of said chamber, an arch dividing said chamber into an upper and a lower compartment communicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting outwardly beyond the said grate, the rear part of the bottom of the chamber being composed of refractory material. and means for causing one kind of fuel to flow from the rear part of the chamber first forwardly to the front end of the lower compartment, then rearwardly to the rear part of the upper compartment and then forwardly along the upper side of the arch before escaping from the chamber, the part of the bottom of the chamber composed of refractory material being inclined upwardly and rearwardly from the" rear end of the grate so'that the whole grate willbe visible through the said firing opening.

5. In a furnace for different kinds of fuel, the combination of a combustion chamber, a firing opening in the rear end wall of said chamber, an arch dividing said chamber into an upper and a lower compartment communicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting rearwardly beyond the said grate, the rear part of the bottom of the chamber being composed of refractory material, and means for causing one kind of fuel to flow from the rear part of the chamber first forwardly to the front end of the lower compartment, then rearwardly to the rear part of the upper compartment and then forwardly along the upper side of the arch before escaping from the chamber, the upper part of the lateral walls of the chamber between the grate and 'the arch being composed of cooled plates and the lower part of said lateral walls being composed of refractory material.

6. In a furnace for different kinds of fuel, the combination of a combustion chamber, a

firing opening in the rear end wall of said compartment and then forwardly along the upper side of the arch before escaping from the chamber, the upper part of the lateral wallsof the chamber between the grate and the arch being composed of cooled plates and the lower part of said lateral walls being composed of refractory material, the lower part of said walls being closer together than said upper part thereof;

7. In a furnace for different kinds of fuel,

the combination of a combustion chamber, a firing opening in the rear end wall of said chamber, an arch dividing said chamber into an upper and a lower compartment communicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting rearwardly beyond the said grate, the rear part of the bottom of the chamber bemg composed of refractory material, means for causing one kind of fuel to flow from.

the rear part of the chamber first forwardly ,to the front end of the lower compartment then rearwardly to the rear part of the upfiring opening in the rear end wall of said chamber, an arch dividing said chamber into an. upper and a lower compartment com- :m'unicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber,sa1d arch projecting rearwardly beyond the said grate, the rear part of the bottom of the chamber being composed of refractory material, means for causing one kind of fuel to'flow from the rear part ofthe chamber first forwardly to they front end of the lower compartment then rearwardly to the rear part vr of-the upper compartment and then forwardly along the upper side of the arch be- I force escaping from the chamber, and a pluralityof air inlets being located in vthe rear part of said bottom of the chamber composed of refractory material, certain of said inlets being positioned above the others.

9. In a furnace for pulverulent fuel, the

I combination of a combustion chamber, a firing opening in the rear. end wall of said chamber," an arch dividing said chamber into an upper and lower compartment 'com municating with each other at the rear part of-the chamber, means for causing one kind of fuel to pas's'along first the lower and then the upper side of the said arch before leaving the chamber, the rear part of the bottom of the chamber being composed of refractory materialland the front part thereof including a grate, a fuel inlet pipe passing through the'rearwall of the chamber and extending forwardly, and a horizontal channel. forming an air inlet arranged in the rear part of the bottom of the chamber, said channel being partially located below the said arch.

10. Ina furnace for different kinds'of fuel, the combination of a combustion chamher, a firing opening in the rear end wall of said chamber, an arch dividing said chamber into an upper and a lower compartment communicating with eachiother at the rear part wees ofthe chamber, a grate inthe front vpart of.

the bottomfof the chamber, said arch pro? jecting outwardlv beyond the said grate, the

rear part the bottom ofv the chamber be I ing composed, of refractory material and means for causing one kind of fuel to flowv from the rear part of the chamber firstfor 11. Ina furnace for different kind's of:

fuel, the combination ofa combustion ichamher, a firing opening in therear end wall'of said chamber, an arch dividing said chamber into an upper and a lower compartment communicating with each other at the rear part of the chamber, a grate in the front part of the bottom of the chamber, said arch projecting rearwardly beyondv the said grate, the rear part of the bottom of the chamber means for causing one kindof fuel to flow of the upper compartment andthen for wardly along the upper side of the arch be: fore escapingfrom the chamber, said grate -being divided, into a plurality ofcsections adapted to swing on ahorizontalaxis. i

12. In a furnace for different kinds of,

fuel, the combination of a combustion cham--. her, a firing opening in the rear end wall, of said chamber, an arch dividing said chamber into an upper and a lower compartment communicating with each otherat the rear part of the chamber, a grate in the front part of the bottom of-the chamber, said arch projecting rearwardly beyondthe said grate, the rear part of the bottom of the chamber being composed of refractory ,material, and means for causing one kind, of fuelto flow from the rear part of the chamber first forwardly to the frontend of the lower compartment then rearwardly to the rear part of the upper compartment and then forwardly along theupper side of the arch before escaping from the chamber, the arch and the part of the bottom of the chamber composed of refractory material below the archconverging rear-wardly.

In testimony whereof I aflix my signature I in presence of two witnesses.

KARL HJALMAR VILHELM von PORAT. Witnesses:

WILMA C. ERIKSON, INEZ SWENSSON. 

